CVE-2021-4120

HIGH

snapd < 2.54.3 - AppArmor Policy Rule Injection via Malformed Content Interface and Layout Declarations

Title source: llm
STIX 2.1

Description

snapd 2.54.2 fails to perform sufficient validation of snap content interface and layout paths, resulting in the ability for snaps to inject arbitrary AppArmor policy rules via malformed content interface and layout declarations and hence escape strict snap confinement. Fixed in snapd versions 2.54.3+18.04, 2.54.3+20.04 and 2.54.3+21.10.1

References (5)

Core 5
Core References
Patch, Vendor Advisory x_refsource_misc
https://ubuntu.com/security/notices/USN-5292-1
Exploit, Issue Tracking, Third Party Advisory x_refsource_misc
https://bugs.launchpad.net/snapd/+bug/1949368
Exploit, Mailing List, Third Party Advisory mailing-list x_refsource_mlist
http://www.openwall.com/lists/oss-security/2022/02/18/2

Scores

CVSS v3 8.2
EPSS 0.0009
EPSS Percentile 25.0%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H

Details

CWE
CWE-20
Status published
Products (6)
canonical/snapd < 2.54.2
canonical/ubuntu_linux 18.04
canonical/ubuntu_linux 20.04
canonical/ubuntu_linux 21.10
fedoraproject/fedora 34
fedoraproject/fedora 35
Published Feb 17, 2022
Tracked Since Feb 18, 2026